Multi-axis wrists are known in the art as exemplified by U.S. Pat. Nos. 3,826,383 and 4,068,536, both of which disclose wrists providing motion about three different axes.
It is the aim of this invention to provide a two-axis wrist module which is of relatively small size and low weight, of relatively simple structure, of a character which also lends itself to being substantially fluid tight and which is basically self-contained in the sense that the drive means for obtaining the two-axis movement is available from the module itself. It is a further aim of the invention to provide a wrist module in which harmonic drive units are contained in the wrist module itself in a fashion to obtain relatively high gear reduction so that the drive means can take the form of high speed, low torque motors.